SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '431b375b4a265b397ecc7212927edab13fb60322eb48f24d57d6067a92ac98e4' 
  AND token = 'WHViJwj40Ty2IaZXl2mZ/wsYcQBXBRTvFKwmpis330w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}